<h3>
Answer:</h3>
Trough
<h3>
Explanation:</h3>
We need to answer the following questions
What is a wave?
- A wave refers to a transmission of a disturbance from one point to another. It involves transfer of energy from the source to other points.
What are the major types of wave?
- Waves may be classified as longitudinal waves or transverse wave based on the vibration of particles relative to the direction of transmission.
What is a transverse wave?
- A transverse wave is a wave in which the vibration of particles is perpendicular to the direction of transmission of the wave.
- This type of wave contains highest points known as crests and lowest points known as troughs.
The answer is true because if you look at the question what does it say
Answer:
Option B is correct.
4
Explanation:
We know that an atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example, if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.
In given problem we are given with 2 neutrons of helium. We know that the atomic number of He is 2. Thus Mass number of He is,
Number of neutrons + number of proton
2 + 2 = 4
Thus, option B is correct.
